A multitechnique approach which aims at elucidating the mechanism of action of the antitumor antibiotic bleomycin is proposed. The work will progress in four parts. The first stage will concentrate on elucidating the structure of biologically inactive, but easy to handle, metallobleomycins. A second part will examine the structure and properties of the biologically active iron bleomycins. Having explored the drug's metal ligating properties, the structural aspects of the complex formed between the drug and DNA and oligonucleotides will be examined. Finally, the structural and dynamic aspects of the biologically important ternary complex metal ion-drug-DNA will be uncovered. It is invisioned that the effort will not only provide a deeper understanding of the mechanism of action of the pharmaceutical but also provide a foundation on which meaningful, therapeutically constructive, modifications of the drug's framework can be based.